Electrical relay

ABSTRACT

AN ELECTRICAL RELAY HAVING A FIELD PIECE WITH A COIL ASSEMBLY AND AN ARMATURE MOUNTED THEREON INCLUDES A FLAT RETURN SPRING WHICH BIASES THE ARMATURE ABOUT ITS PIVOTAL MOUNTING ON THE FIELD PIECE AND SIMULTANEOUSLY HOLDS THE ARMATURE IN POSITION ON THE FIELD PIECE. ALSO AN IMPROVED SPOOL CONSTRUCTION FOR THE COIL ASSEMBLY INCLUDES A FLANGE ADAPTED TO RECEIVE THE LEAD WIRES OF THE COIL WINDING.

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ELECTRICAL RELAY 2 Sheets-Sheet 2 Filed Jan. Q7, 1969 United StatesPatent O 3,553,616 ELECTRICAL RELAY John J. Rowell, Glenview, andWilliam W. Wright,

Wheaton, lll., assignors to Guardian Electric Manufacturing Company,Chicago, Ill., a corporation oi' Illinois Filed Jan. 27, 1969, Ser. No.794,136 Int. Cl. H01h 3/54 U.S. Cl. 335-187 1 Claim ABSTRACT OF THEDISCLOSURE An electrical relay having a field piece with a coil assemblyand an armature mounted thereon includes a fiat return spring whichbiases the armature about its pivotal mounting on the field piece andsimultaneously holds the armature in position on the field piece. Alsoan improved spool construction for the coil assembly includes a flangeadapted to receive the lead Wires of the coil Winding.

BACKGROUND OF THE INVENTION This invention relates to an improvedelectrical relay and, in particular, to an electrical relay having anarmature connected with a field piece by means of a flat return spring.

A common construction of an electrical relay provides for an armaturewhich is pivotally attached to a field piece. A coil is mounted tomagnetically drive the armature in one direction toward the coilWhenever current passes through the coil. The armature is mechanicallybiased away from the coil by means of a spring, for example, a spiralspring which is attached between the relay housing and the armature.Thus, a contact mounted on the armature moves with the armature to makeand break an electrical circuit as the armature is alternativelyattracted magnetically by the coil and biased mechanically by thespring.

On relays of the type using a spiral spring to bias the armature, thespring must be suspended at some distance from the armature pivot pointto achieve proper mechanical leverage. Thus, valuable volume in thetotal configuration of the relay is required for the armature biasingspring. Of course, it is very desirable when designing a unit of thistype to` provide for maximum performance in a minimum volume. Byeliminating the spiral spring and substituting a multi-purpose flatspring, the relay of the present invention minimizes volume requirementswithout any loss in relay capacity.

Another important consideration in an electrical relay unit is theconstruction of the electrical coil which magnetically drives thearmature. It is important that the spool upon which the coil windingsare wound be designed to permit rapid winding, and insure that the wireleads of the windings will not accidentally cross and short circuit. Thesubject matter of the present invention provides a novel spoolconstruction satisfying these criteria.

Finally, it is desirable to minimize the number of parts in anelectrical relay, maximize the performance and load that may be carredby the relay, and minimize the cost and time of assembly of theelectrical relay, The present invention provides all of these advantagesover prior art relays.

SUMMARY OF THE INVENTION In a principal aspect the present invention isthe improvement, in an electrical relay of the type having an armaturepivotally mounted on a field piece and a coil assembly for magneticallydriving the armature, of a fiat spring for simultaneously holding thearmature in communication with the field piece and mechanically biasingthe armature outwardly from the magnetic coil assembly. Further, thecoil preferably includes a peripheral recess about a flange of the spoolupon which the coil windings are wound so that the two leads from thecoil are separated from one another and protected from abrasion andshort circuiting.

It is thus an object of the present invention to provide an improvedelectrical relay which minimizes unit volume by providing a flat springfor mechanically driving the armature.

Another object of the present invention is to provide an improvedelectrical relay which utilizes a flat spring to hold the armature onthe field piece and simultaneously mechanically biases the armatureoutwardly from the coil assembly.

It is a further object of the present invention to provide an improvedelectrical relay comprised of a minimum number of component partsoccupying a minimum volurne.

It is still another object of the present invention to provide animproved electrical relay which is easy to assemble and economic tomanufacture.

One further object of the present invention is to provide an improvedelectrical relay having an improved coil construction which providesimproved protection to the wire leads of the electrical coil.

These and other objects, advantages and features of the presentinvention will be set forth in greater detail in the description whichfollows:

BRIEF DESCRIPTION OF THE DRAWING In the detailed description whichfollows reference will be made to the drawing comprised of the followingfigures:

FIG. l is a side View of the improved electrical relay of the presentinvention;

FIG. 2 is an end view of the relay shown in FIG. l and ilustrates thecontact lug configuration for the relay;

FIG. 3 is a top plan view of the relay shown in FIG. l;

FIG, 4 is a cross sectional view of the relay shown in FIG. l takensubstantially along the line 4 4;

FIG. 5 is an enlarged cross sectional view of the lugs shown in FIG. 2taken substantially along the line 5 5;

FIG. 6 is a top cross sectional view of the lugs shown in FIG. 5 takensubstantially along the line 6 6;

FIG. 7 is an enlarged top plan View of the relay illustrating therelationship of the flat sprng and the armature;

FIG. 8 is a cross sectional view of the armature assembly takensubstantially along the line 8 8 in FIG. 7;

FIG. 9 is a side view of the spool for electrical windings in the coilassembly of the relay;

FIG. 10 is a left hand end view of the spool in FIG. 9;

FIG. 11 is a right hand end view of the spool in FIG. 9;

FIG. 12 is a side elevation of the at armature return spring used in therelay;

FIG. 13 is an end view of the spring in FIG. 12; and

FIG. 14 is a top view of the spring in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1, 3 and4 there is shown the construction of a relay incorporating the featuresof the present invention. The relay includes a field piece 10 which isrigidly attached to a terminal block 12 by means of a threaded bolt 14extending from the field piece 10` and passing through an opening in theterminal block 12. The terminal block 12 is preferably fabricated froman insulating material such as alkyd or diallylthalate. The field piece10 is preferably fabricated from metal such as a magnetic iron. A nut 16secures the field piece 10 against the terminal block 12. A clearplastic relay cover 18 encloses the entire relay assembly.

The field piece includes an armature mounting member 20 and a coilassembly mounting member 22. An armature assembly 24 and a coil assembly26 are attached to the mounting members 20 and 22 respectively.

The coil assembly, as illustrated in FIGS. l and 4, includes a moldedplastic spool 28. The spool 28 illustrated in FIGS. 9-1l, includes abottom fiange 30, a top flange 32 and an interconnecting core section34. The spool 28 preferably is molded from a polycarbonate resin, anonconductive material. The core section 34 is cylindrically shaped andadapted to receive coil windings about its outer surface. The wound coilis preferably covered by insulating tape 33 as shown in FIG. l. The coilwindings may be wrapped around the core section 34 in either theclockwise or counterclockwise direction.

Positioned on the inside of the core section 34 is a magnetic metal core36 as illustrated in FIG. 4. The core 36 passes through the core section34 and is fastened to the coil assembly mounting member 22. Spool 28 ismounted on the core 36. A shading ring 38, fabricated of copper,cooperates with the core 36 to hold the spool 28 in position. Theshading ring 38 is positioned in a shaped depression 40 in the topfiange 32.

Top flange 32 also includes a pair of grooves or recesses 41 and 42around the outer periphery of the top flange 32. The recesses 41 and 42are smooth surfaced, continuous grooves having no sharp corners whichmight sever or cut lead wires and 52 from the coil. Recess 41 is thestart side recessand receives the starting lead 50 of a wire Winding.Recess 42 is the finish side recess and receives the finish end lead ofa winding.

The recesses 41 and 42 terminate at a slot 44 defined in the bottomportion 33 of the top flange 32 as illustrated in FIG. 11. Slot 44 isdimensionally wider than the sums of the diameters of lead wires, 50 and52 in FIG. 4. This insures that lead wires will not cross or short thecoil. Start side recess 41 forms an acute angle with one side of slot 44whereas finish side recess 42 substantially coincides with the oppositeside of recess 44. This further insures that the lead wires will notcross or short circuit.

In addition, the top flange 32 of the spool 28 has a pair of integrallymolded lead wire ears 46 and 48. The lead wires 50 and 52 from the coilare twisted around the ears 46 and 48, respectively. Thus, ear 46receives the start side lead lwire 50 of a coil winding. Ear 48 thenreceives the nish side lead wire 52 of a coil. Each lead wire 50 and 52is connected to an appropriate coil control lug 87 and 88 respectively.This construction and arrangement of the recesses in the top fiange 32along with the ears 46 and 48 pro-vides for greatly improved ease ofWinding and manufacture and results in savings due to acceleration ofmanufacture and assembly of the relay.

Referring now to FIGS. l-S, the armature assembly 24 is attached to thearmature mounting member 20 of the field piece 10. The assembly 24includes 4 contact blades 54 through 57 which are molded in a block 58.Because the blades 54-57 are molded in position, proper alignment ofcontacts mounted on the blades with contacts on the various lugs interminal block 12 is assured. The block 58 is rigidly attached to anarmature 60. The block 58 is fabricated from an insulating material sothat the armature 60 and blades 54 through 57 are electrically insulatedfrom one another.

The armature 60 is pivotally mounted on the mounting member 20 and heldin position on the mounting member 20 by means of a flat spring 62.Mounting member 20 includes first and second projections 64 and 66 whichextend outwardly from mounting member20 and loosely fit through openingsor recesses 68 and 70 defined in the armature 60. A flat blade orbushing 71 is inserted between the armature 60 and mounting member 20 inthe area between the projections 64 and 66.

As illustrated in FIGS. 1214, flat spring 62 includes a field piece end72 and an armature end 74. Field piece end 72 is shaped to fit throughan opening 76 in the mounting member 20 as shown in FIGS. l or 4. Themajority of the length of the field piece end 72 is positioned on theside of the field piece opposite the coil assembly 26; whereas, theextremity of the field piece end 72 is shaped to fit `through theopening 76 and against the side of the field piece adjacent the coilassembly 26. The flat spring 62 also includes in the field piece end 72`a tab 78 which cooperates With one side of the opening 76 to facilitateholding the spring 62 in tight communication with the member 20.

The armature end 74 of the spring 62 fits through a slot 80 in the block58 as shown in FIGS. l, 3 and 8. The spring 62 is slidably received bythe slot 80; however, a tab 82 in the armature end 74 lockingly engagesthe block 58 following insertion through the slot 80 and cooperates withthe spring extensions or wings 84 and 85 on the opposite side of thelblock 58. Thus, the fiat spring 62 is held in a fixed position inrelation to the armature assembly 24.

The `flat spring 62 is biased to drive the blades 54 through 57 in acounterclockwise direction about the pivot point defined by the armature60 and field piece 20. Thus, the flat spring 62 drives contacts on theblades 54-57 into a closed circuit position with contacts on lugs105-108. Simultaneously, since the flat spring 62 is locked in contactwith the armature 60 and field piece 20, it serves to hold the armature60 in position relative to the field piece 20. In FIG. l2, the phantomlines indicate the free position of the spring 62 and the solid linesindicate the assembled position. The spring 62 provides a uniform backtension to the armature 60.

To move the armature 60 by electric signal means, current is introducedthrough the coil assembly 26. This, in turn, causes a magneticattraction of the armature 60l to the core 36 thereby depressing theblades 54 through 57 in a clockwise direction about the axis of rotationof the armature 60 and the field piece 20. As shown in FIG. 2 the coilassembly 26 is activated whenever current is introduced through controlcoil lugs 87 and 88.

Current input through armature connected lugs 94 through 97 passesthrough lead wires 114-117 respectively, then through the blades 54through '57 respectively, the contacts on the ends of the blades 54through 57 and finally through a set of output lugs 101 through 104 or105 through 108. Thus, when the coil is not activated contacts as at 98on blade 57 connect with output contacts as at 99 on lug 105. When thecoil is activated and the armature 60 is depressed the double-headedcontact 98 makes a junction with the contact 100 attached to lug 104.

IFIGS. 5 and 6 provide an enlarged view of the connection of the lugs tothe terminal block 12. As can be seen in these figures the lugs 104 and105 include formed tabs as at on lug 105 which cooperate with recessesin the terminal block and with a bent tab as at 91 on lug 105 to holdthe lug 105 in position in the terminal block 12. In this manner thelugs can be precisely positioned in the terminal block and better serveto hold the contacts on the ends of the lugs in an affixed, rigidposition. Thus, proper intersection of the contacts on the ends of theblades 54 through 57 is assured with contacts on the lugs 101-104 or105-108.

What is claimed is:

1. In an electrical relay of the type having a field piece, a magneticcoil assembly in fixed relation with said field piece, an armaturepivotally mounted on said field piece and held from longitudinalmovement by lugs extending from said field piece through recesses insaid armature at the pivotally mounted position of said armature on saidfield piece, said armature magnetically responsive to said coilassembly, said armature drivingly connected with at least one contact soas to drive said contact against second contact means to make and breaka circuit whenever said coil assembly acts to induce motion to saidarmature,

said armature normally being biased away from said coil through saidopening in said field piece and engaging assembly about the pivotalmounting of said armature the inside of said field piece adjacent saidcoil to with said field piece, the improvement of: hold said field pieceleg against said field piece.

a single, flat, removable, return spring for simultaneously holding saidarmature in said pivotally 5 References Cited mounted position againstsaid field piece and mechanically biasing said armature away from saidcoil UNITED STATES PATENTS assembly in a direction opposite said inducedmotion, 2,856,492 10/ 1958 Heyhal 200-166(ICTS) said return springincluding an armature leg and a 2,916,580 1'2/1959 Seele 335 1g7 yfieldpiece leg, said armature including a Contact 10 3,023,286 2/1962 Bourne335 187 mounting block with a slot therethrough extending 3,051,804g/1962 Mayer 335 1g7 toward said pivotally mounted position forreceiving 3,054,871 9/ 1962 Skay 200-166(\ICTS) said armature leg ofsaid return spring, said armature 3,035,139 4/1963 Wright 200l66(I\CTS)leg including at least one tab and one wing which 3,230,489 1/1966Weyrich 336 192 engage said mounting block on opposite sides thereof 153,308,407 3/1957 Lake 33 5 187 to hold said armature leg in fixedrelation with said mounting block, said field piece including an open-HAROLD BROOME, Primary Examiner ing therethrough, said field piece legpositioned against said field piece on the side opposite said coil U.S.Cl. X.R. assembly and including an extremity tab passing 20 200--166

